Low-Cost Rain Gauge Looks for Floods

We’ve seen a lot of uses for the now-ubiquitous ESP chip, including a numerous wilderness-monitoring devices.

Pluvi.on stands out with some attractive solutions and a simple design.

A lot of outdoor projects involve some sort of stock weather-resistance enclosure, but this project has a custom-designed acrylic box. About 4 inches across, the gauge uses a seesaw-like bucket to measure rain—a funnel, built into the enclosure, sends water into the gauge which records each time the bucket mechanism tilts, thereby recording the intensity of the rain. A NodeMCU packing an ESP8266 WiFi SoC sends the data to the cloud, helping predict the possibility of a flood in the area.

I first saw this see-saw design in a hydrographic station on top of Table Mountain (Cape Town). The see-saw was made of brass, and the station was already about 100 years old. Every time it seed or sawed (are those words?) it moved a pen pointer up a paper chart on a roller that (used to) rotate slowly to record when and how much rain fell.

There is also a $15 rain gauge sensor with the same principle in mind on aliexpress.

It’s from a cheap Chinese weather station, it has a reed switch and a cable. A lot of people have hacked it before online.

I think it would be easier to order it and hack it, than to 3D print it, although it would also depend on the situation. A funnel could also be added to cover a larger area of rainfall, thus increasing accuracy.